Solid state imaging device and method of manufacturing the same

Abstract

A solid state imaging device has a plurality of photodetector parts 11 arranged in matrix, a plurality of vertical charge transfer electrodes 13 that read out signal charge from the photodetector parts and transfer the signal charge in the vertical direction, and a first light-shielding film 5 that shields the plural vertical charge transfer parts from incident light. Each of the vertical charge transfer electrodes includes: a transfer channel 12 provided along the vertical array of the plural photodetector parts, a plurality of first transfer electrodes 3 a that are formed on the transfer channel so as to traverse the transfer channel and that is coupled in the horizontal direction in spacing between the photodetector parts; and second transfer electrodes 3 b provided on the transfer channel and arranged between the first transfer electrodes. The first light-shielding film is formed continuously in the horizontal direction and has openings formed on the photodetector parts. Isolation regions having electroconductivity are formed between the photodetector parts and connected electrically to the second transfer electrode. Thereby, a shunt wiring structure capable of a high-speed transfer at a high sensitivity and with reduced smearing is obtained.

1. A solid state imaging device comprising:
 a plurality of photodetector parts that are arranged in matrix on a semiconductor substrate and that convert incident light into signal charge, 
 a plurality of vertical charge transfer parts that read out the signal charge from the photodetector parts and transfer the signal charge in the vertical direction, and 
 a first light-shielding film that shields the plural vertical charge transfer parts from the incident light; 
 wherein each of the plural vertical charge transfer parts comprises: a transfer channel provided on the semiconductor substrate along the vertical array of the plural photodetector parts, a plurality of first transfer electrodes that are provided on the transfer channel so as to traverse the transfer channel and that are coupled to each other in the horizontal direction in spacing between the photodetector parts, and a second transfer electrode that is provided at least on the transfer channel and arranged between the first transfer electrodes; and 
 the first light-shielding films having electroconductivity are formed continuously in the horizontal direction, with openings on the photodetector parts and isolation regions formed between the photodetector parts so as to extend in the horizontal direction, the first light-shielding films being connected electrically to the second transfer electrode. 
 
     
     
       2. The solid state imaging device according to  claim 1 , wherein the isolation regions of the first light-shielding film are formed on the first transfer electrodes. 
     
     
       3. The solid state imaging device according to  claim 1 , comprising a second light-shielding film that passes between the photodetector parts adjacent to each other in the vertical direction and that covers the isolation regions of the first light-shielding film and traverses the transfer channels, the second light-shielding film having electroconductivity and being connected electrically to the first transfer electrodes. 
     
     
       4. The solid state imaging device according to  claim 3 , wherein connection parts between the first transfer electrodes and the second light-shielding film are provided on electrodes in a region outside the vertical charge transfer parts. 
     
     
       5. The solid state imaging device according to  claim 3 , wherein the second light-shielding film is arranged above the first light-shielding film. 
     
     
       6. The solid state imaging device according to  claim 3 , wherein the second light-shielding film is formed so that the side edge is positioned between the side edge of the first light-shielding film facing the isolation region and the side edge of the first light-shielding film at the photodetector part side. 
     
     
       7. The solid state imaging device according to  claim 1 , wherein the second transfer electrodes comprise a material having a low resistance in comparison with polysilicon. 
     
     
       8. The solid state imaging device according to  claim 7 , wherein the second light-shielding film comprises at least on the upper surface a light-shielding metallic material that has a low resistance in comparison with the polysilicon. 
     
     
       9. A method of manufacturing a solid state imaging device comprising: a plurality of photodetector parts that are arranged in matrix and that convert incident light into signal charge, a plurality of vertical charge transfer parts that read out the signal charge from the photodetector parts and transfer the signal charge in the vertical direction, and a light-shielding film that shields the plural vertical charge transfer parts from the incident light, the method comprising steps of:
 (a) forming on a semiconductor substrate the plural photodetector parts and transfer channels each arranged along the vertical array of the plural photodetector parts; 
 (b) forming the plural vertical charge transfer parts by providing on the transfer channel a plurality of first transfer electrodes that traverse the transfer channel and are coupled in the horizontal direction in spacing between the photodetector parts, and second transfer electrodes that are provided at least on the transfer channel and between the first transfer electrodes; 
 (c) forming a first interlayer insulating film that covers the plural transfer electrodes; 
 (d) forming on the first interlayer insulating film an electrically conductive film that covers the first interlayer insulating film and that is connected electrically to the second transfer electrodes; and 
 (e) forming a light-shielding film by processing the electrically conductive film to form openings on the photodetector parts and form isolation regions between the photodetector parts, the isolation regions extending in the horizontal direction with respect to the first transfer electrodes. 
 
     
     
       10. The method of manufacturing a solid state imaging device according to  claim 9 , wherein in step (e), the step of forming the openings and the step of forming the isolation regions are carried out respectively as separate steps.